An article (abbreviated art) is a word that combines with a noun to indicate the type of reference being made by the noun. Articles specify the grammatical definiteness of the noun, in some languages extending to volume or numerical scope. The articles in the English language are the and a/an, and (in some contexts) some. 'An' and 'a' are modern forms of the Old English 'an', which in Anglian dialects was the number 'one' (compare 'on', in Saxon dialects) and survived into Modern Scots as the number 'ane'. Both 'on' (respelled 'one' by the Normans) and 'an' survived into Modern English, with 'one' used as the number and 'an' ('a', before nouns that begin with a consonant sound) as an indefinite article.

In some languages, articles are a special part of speech, which cannot easily be combined with other parts of speech. It is also possible for articles to be part of another part of speech category such as determiner, an English part of speech category that combines articles and demonstratives (such as 'this' and 'that').